Stable incidence and survival of arteriovenous fistulas over 39 years: A long-term national cohort study.

INTRODUCTION: The age and number of comorbidities in the hemodialysis population has increased over time. This may influence the construction and survival of the arteriovenous fistula (AVF). The present study explored the incidence and survival of AVFs over a period of 39 years. METHODS: A retrospective cohort study was conducted based on Danish registries. Incident hemodialysis patients between 1977 and 2015 were included. The incidence of AVF and factors associated with the construction of an AVF were described. Risk factors for AVF survival and repair were explored by Kaplan Meier and Cox proportional hazard analysis. RESULTS: The total number of arteriovenous accesses (AVF and arteriovenous grafts) were 10,187 and there were 4201 central venous catheters (CVC). No significant difference in the proportion of AVFs during the 39 years was seen. Age and renal diagnosis did not influence the proportion of AVFs. Patients with CVCs were found to have a significantly higher prevalence of comorbidities (p < 0.01). AVF survival remained stable during the 39 years. The first constructed AVF had the best survival, 35% still functioning after 15 years. Factors such as brachiocephalic AVF, female sex, and diabetic nephropathy increased the risk of AVF failure (Odds Ratio (OR): 2.46, 95% Confidence Interval (CI) (2.29-2.65), 1.17 (1.10-1.25), and 1.21 (1.12-1.3)), respectively. CONCLUSION: Despite an older dialysis population, the proportion and survival of the AVF in the Danish dialysis population has not changed, probably because of increased awareness of AVF as the first choice of vascular access and improved surveillance, surgery, and repair.

Mitochondrial dysfunction in calf muscles of patients with combined peripheral arterial disease and diabetes type 2.

BACKGROUND: This study elucidates the effects on muscle mitochondrial function in patients suffering from combined peripheral arterial disease (PAD) and type 2 diabetes (T2D) and the relation to patient symptoms and treatment. METHODS: Near infrared spectroscopy (NIRS) calf muscle exercise tests were conducted on 40 subjects, 15 (PAD), 15 (PAD+T2D) and 10 healthy age matched controls (CTRL) recruited from the vascular outpatient clinic at Gentofte County Hospital, Denmark. Calf muscle biopsies (~80 mg, gastrocnemius and anterior tibial muscles) were sampled and mitochondrial function tested applying high resolution oxygraphy on isolated muscle fibers. RESULTS: The NIRS exercise tests showed evidence of mitochondrial dysfunction in the PAD+T2D group by a longer recovery of the deoxygenation resulting from exercise in spite of a higher exercise oxygenation level compared to the PAD group. This was confirmed by a ~30% reduction in oxygen consumption in the muscle biopsy tests for the PAD+T2D compared to the PAD group (P<0.05). We claim that this mitochondrial dysfunction partly explains the ~30% reduction in tread mill walking distance for the PAD+T2D group observed in this study. CONCLUSIONS: These findings support the use of early surgical revascularization in the PAD+T2D group, in order to obtain better walking performance and probably reduced risk of permanent mitochondrial damage.